Synthesize of α, β-Unsaturated Schiff-Based Complexes for Hydrogen Storage Application

In this study, a novel ligand, denoted as LBr, was synthesized through the condensation reaction between 2-hydroxyaniline and 2-(5-Bromo-3,3-dimethyl-1,3-dihydro-indol-2-ylidene)-malonaldehyde. The new ligand was thoroughly characterized using 1H- and APT 13C-NMR, FTIR, and elemental analysis. The ligand was used to synthesize a series of new complexes by reacting it with cobalt, nickel, copper, and zinc chlorides. The complexes were characterized by FTIR, CHN analysis, AAS, µ-effective, and conductivity measurements besides other physical properties of both the ligand and its complexes were also determined. The results demonstrated that all complexes exhibited an octahedral geometry. The prepared complexes were utilized in hydrogen storage application to determine the significance of the central metal type in enhancing the gas storage capacity at a single pressure condition, which was 50 bar at a temperature of 77 K. The measurements demonstrated that the metal type significantly influences hydrogen storage capability. The recorded storage capacities were 2.03, 1.91, 1.86, and 1.80 wt.% for nickel, copper, zinc, and cobalt, respectively.